TRANSCRIBER'S NOTE Italic text is denoted by _underscores_. Bold text is denoted by =equal signs=. A subscript x is denoted by _{x}, for example H_{2}O. Footnote anchors are denoted by [number], and the footnotes have been placed at the end of the book. Some minor changes to the text are noted at the end of the book. THE UNSEEN UNIVERSE ... μὴ σκοπούντων ἡμῶν τὰ βλεπόμενα, ἀλλὰ τὰ μὴ βλεπόμενα· τὰ γὰρ βλεπόμενα, πρόσκαιρα· τὰ δὲ μὴ βλεπόμενα, αἰώνια. Πρὸς Κορινθίους, Βʹ. δʹ. Animula! vagula, blandula, Hospes comesque corporis, Quae nunc abibis in loca,— Pallidula, rigida, nudula.... HADRIAN. ‘God hath endowed us with different faculties, suitable and proportional to the different objects that engage them. We discover sensible things by our senses, rational things by our reason, things intellectual by understanding; but divine and celestial things he has reserved for the exercise of our faith, which is a kind of divine and superior sense in the soul. Our reason and understanding may at some times snatch a glimpse, but cannot take a steady and adequate prospect of things so far above their reach and sphere. Thus, by the help of natural reason, I may know there is a God, the first cause and original of all things; but his essence, attributes, and will, are hid within the veil of inaccessible light, and cannot be discerned by us but through faith in his divine revelation. He that walks without this light, walks in darkness, though he may strike out some faint and glimmering sparkles of his own. And he that, out of the gross and wooden dictates of his natural reason, carves out a religion to himself, is but a more refined idolater than those who worship stocks and stones, hammering an idol out of his fancy, and adoring the works of his own imagination. For this reason God is nowhere said to be jealous, but upon the account of his worship.’—_Pilgrims Progress_, Part III. ‘To die,—to sleep;— To sleep! perchance to dream;—ay, there’s the rub; For in that sleep of death what dreams may come, When we have shuffled off this mortal coil, Must give us pause.’—SHAKESPEARE, _Hamlet_, Act iii. Scene 1. [Illustration: (decorative icon)] THE UNSEEN UNIVERSE OR PHYSICAL SPECULATIONS ON A FUTURE STATE BY B. STEWART AND P. G. TAIT. ——the things which are seen are temporal, but the things which are not seen are eternal. _SEVENTH EDITION_ (_Revised, and Enlarged._)